Pre '96 Suzuki DR650S

[Cobain]

Very cool banjo, good to see your still rocking the old school.

[rowie]

This seller has had this frame (to suit 1990 / 1991) listed for over 12 months. He must be tired of looking at it because the starting bid is $29.99!

http://www.ebay.com/itm/360551363925

The seller is in Israel, so the freight cost is a bit steep.

[GRinCR]

Hi all,

I am going to crack her open. I am replacing the rings/piston, cam chain guide/tesioner and curiosity has me wanting to snoop around since the bike has 50K+Km on it and the engine will already be out.

Any leads on a good gasket set for this bike? I have seen a few, but in Europe.

Anything particular to "beware" of? I am a novice (great at oil changes), but will have a certified mechanic standing watch over me. Still scared sh*tless none the less.

Mil Gracias

[motolab]

Originally Posted by GRinCR

Any leads on a good gasket set for this bike?

I would use the Vesrah, but as far as I know, there is a 4 month lead time to get one.

Regards,

Derek

[rowie]

Doing the 1000k service today and popped the stator cover off to tension the balancer chain and fit the additional small chain guide that is fitted to the 92 - 95 models. I set up the timing per the manual when re-assembling the motor, but I noticed the timing marks did not line up with TDC.

All looks good here:



However, the TDC mark on the rotor does not line up with the mark on the case (arrowed)



When I align the rotor with the case:



It throws the chain marks out by one tooth.



I asked a mechanic mate about it and he suggested spinning the crank until the marks lined up again as there is only one location where they should be all aligned. It takes 18 revolutions of the crank for them marks to line up again and there is no change. Does the chain have to be timed to exactly TDC or is it correct now? There doesn't appear to be any abnormal vibrations, and I have nothing to compare it to. Just figured I would fix it (if it needs it) while the cover is off.

Cheers,
David

[pistaMunno]

How much fuel does the dr 650 RSE '90 original tank holds including the reserve? Rowie ?

[rowie]

Originally Posted by pistaMunno

How much fuel does the dr 650 RSE '90 original tank holds including the reserve? Rowie ?

21 litres, according to this site: http://www.suzukicycles.org/DR-series/DR650.shtml I guess the reserve capacity is 4.5 litres (or there abouts)

[Ladder106]

Rowie,

Not familiar with the 650 but there is a similar system on the 750/800.

Does the manual tell you how many chain pins there should be between the two sprockets.

If your timing chain was very loose it IS possible to have it jump a tooth or two. I think this generally happens on "shut-down" when the big piston can sometimes turn backward for half a turn or so. This plays hell with the starter gear train unless some sort of "backtorque" system is used by Suzuki (again, not familiar with the 650). I shut my big singles off by using the decomp lever.

I'd guess putting the balancers back into phase as per the manual would improve the smoothness of the engine. I just don't know what reference marks the 650 uses. On the 750, you put the balancer sprockets in a specific position, crank at TDC and then count chain pins/links between the two sprockets.

..............................................

After studying the larger version of your photos, I'd say your crank was off by 1 link.

What sort of tensioner system does the 650 use? Is it at the limit of it's travel?

At least on the 750, there is almost no slack at all detectable in the chains when properly adjusted. It is possible you need a new balancer chain if the tensioner is backed out all the way and the system is still slack.

In any case, I'd correct the misalignment here and expect a much smoother running engine.

[pistaMunno]

Originally Posted by rowie

21 litres, according to this site: http://www.suzukicycles.org/DR-series/DR650.shtml I guess the reserve capacity is 4.5 litres (or there abouts)

Yep saw that just wasn't sure was correct as the first RSE is listed from 1991 but mine is a '90.
Anyway still buyng bits for my rebuild/upgrading, after studying yours (thank you it's awesome by the way), I was thinking about the 25L Acerbis for the pre '96 but probably not worth the fuss for only 4 extra liters? Unless having a plastic tank is better than the stock metal one?
http://justgastanks.com/product_info...roducts_id=335

[rowie]

Originally Posted by Ladder106

Rowie,

Not familiar with the 650 but there is a similar system on the 750/800.

Does the manual tell you how many chain pins there should be between the two sprockets.

If your timing chain was very loose it IS possible to have it jump a tooth or two. I think this generally happens on "shut-down" when the big piston can sometimes turn backward for half a turn or so. This plays hell with the starter gear train unless some sort of "backtorque" system is used by Suzuki (again, not familiar with the 650). I shut my big singles off by using the decomp lever.

I'd guess putting the balancers back into phase as per the manual would improve the smoothness of the engine. I just don't know what reference marks the 650 uses. On the 750, you put the balancer sprockets in a specific position, crank at TDC and then count chain pins/links between the two sprockets.

..............................................

After studying the larger version of your photos, I'd say your crank was off by 1 link.

What sort of tensioner system does the 650 use? Is it at the limit of it's travel?

At least on the 750, there is almost no slack at all detectable in the chains when properly adjusted. It is possible you need a new balancer chain if the tensioner is backed out all the way and the system is still slack.

In any case, I'd correct the misalignment here and expect a much smoother running engine.

Thanks mate. It has a similar setup as the 750.



The chain is new and this was the first adjustment. I double checked and the timing is the same as shown in the manual. For the 90 and 91 models, the procedure shown in the manual doesn't say the engine has to be on TDC. It does have to be on TDC for the 93 to 95 models, which possibly has something to do with the different sprockets that are used.

I have compared the vibrations to a couple other thumpers that also have balance shafts and they are pretty much the same. The bike is back together again now, so I will leave it be until the chain needs tensioning again. Won't take long to re-time it if it is out by one tooth.

Cheers,
David

[rowie]

Originally Posted by pistaMunno

Yep saw that just wasn't sure was correct as the first RSE is listed from 1991 but mine is a '90.
Anyway still buyng bits for my rebuild/upgrading, after studying yours (thank you it's awesome by the way), I was thinking about the 25L Acerbis for the pre '96 but probably not worth the fuss for only 4 extra liters? Unless having a plastic tank is better than the stock metal one?
http://justgastanks.com/product_info...roducts_id=335

Unless your original tank is stuffed or you are planning trips where there is a limited number of servo's, I don't think it would be worthwhile going with the larger tank. So far I have averaged 18.5km/l with the FCR carb and I know another owner in Melbourne that averages 21km/l with the stock carb. I go onto reserve after about 300km and the theoretical range is around 370km ( leaving 1 litre that sits in the lower sections at the front of the tank)

I won't be changing to a plastic tank because the fairing wont bolt onto it

Cheers,
David.

[Ladder106]

For the 90 and 91 models, the procedure shown in the manual doesn't say the engine has to be on TDC. It does have to be on TDC for the 93 to 95 models, which possibly has something to do with the different sprockets that are used.

Rowie,

Am in the midst of this with my DR800 as we speak. I'm noticing that things don't line up perfectly when the crank is at TDC.....just about 1/2 link off.

Thinking about it make me feel like I was in error when I said you were one tooth off. Here's why:

To time the balancer shafts, all that really HAS to happen is for the correct number of chain links to be present between the index mark on the crank, the first (rear) balancer shaft and the correct number of links/pins bewteen the crank, rear shaft and the front shaft.

The shafts don't really care if the crank is at TDC or not as long as the spacing between the shafts (correct number of chain pins) is maintained, they HAVE to be in phase with the crank.

So....the only time TDC is really important is when you are installing the cam. Then the crank MUST be at TDC to get valve timing correct.

It seems your engine is running well and not bouncing out of the frame so I'd bet you are all correct.

Maybe reality is just a bit off from the engineering drawings in the manual.

Thanks for including the photos. The only difference between the 650 and the 750/800 is the length between the two balancer shafts and a bit of a longer timing chain. The tensioner and adjusters are identical.

As a side note:

I've found it beneficial, when adjusting the tension to do this:

Put a wrench on each of the two balancer shafts, loosen the two adjuster bolts, then gently push the two wrenches on the shafts in opposite directlons. What you are doing is purposefully tightening the chain run between the two shafts and allowing ALL the slack to occur below this point in the system. Then the spring can take up all of any existing slack.

It's nice to have one helper to tighten the tensioner screws back down while you're holding the two wrenches on the balancer shafts...otherwise you kinda run out of hands.

[pistaMunno]

Thank Rowie
I'll keep the original than so I can put the money towards another mod .
Just starting to taking the engine apart! i"m twitching haha ..
Also browsing thru your posts to see what you have changed/replaced on the mechanical side so I can follow your footsteps... unless you have a list of things to change/replace while opening a 90.000km engine that's been sitting for a while ?

[dr_man]

Originally Posted by pistaMunno

Thank Rowie
I'll keep the original than so I can put the money towards another mod .
Just starting to taking the engine apart! i"m twitching haha ..
Also browsing thru your posts to see what you have changed/replaced on the mechanical side so I can follow your footsteps... unless you have a list of things to change/replace while opening a 90.000km engine that's been sitting for a while ?

But would plastic Acerbis pre-'96 tank fit '90-'91 model? '92-'95 frame is slightly different.

[GRinCR]

For anyone else out there who may be looking, I think I hit the jackpot. I found a complete gasket kit in the UK that ships to the US for $105.
http://www.wemoto.com/bikes/suzuki/d..._athena_italy/ (Anything bad on Athena gaskets?)

So nice to know this will work as it is made and labeled specifically for my engine number (sp42a)!! If all works I will be singing their praises. They had gasket sets for many, if not all of the pre '96 models.

---------------------------------------------------------------------------------------------------------------------------------

Let me give a bit of a rundown before the questions. I have a 1990 RS much like Rowie's, but blue.
I am trying to quiet down some engine noise and stop it from burning oil and pushing a greasy, carbon substance out the exhaust. In the past the top end has been half assed re-done by Costa Rican Suzuki mechanics. The rocker arms were replaced twice and the cam is new-ish.

I am going to do the over haul with a very close friend who is also a certified mechanic with all the tools. We assume some dip sh*t ran it out of oil. Time will tell what we find but this is the game plan thus far with the hopes of not having to replace much more.

THE PARTS LIST:
-New piston and rings.
-Cam chain, sprockets, guides and tensioner.
-New valves and valve guides and retainers.
-New oil pump

Right now the budget is stretched at that, but with a 22 day delivery time on the gaskets to the US and another week to Costa Rica I can save a bit more coin for all the wonderful surprises.

We plan to split the case with the idea of inspecting everything and if it is toasted, replace it. God willing, the list above will cover it and my fingers are crossed. We took a listen with the stethoscope and she (the mechanic) says the sound is in the right side of the engine and is not a "tappy" sound like valves and sounds like the cam chain. No noise from the magneto side and there is some noise from the top, but it is unexplainable.

QUESTIONS:
1.) Is the balancer chain assembly and are all the sprockets replaceable without splitting the case?
-I ask because if this isn't completely f'ed the wallet would be happy and I can always replace at a later date, maybe by myself.
2.) The cam chain, bottom sprocket is connected to?

Thanks to all so far for answering my questions and there will likely be more to come. I will do a write up on this little project once it starts in thanks to those who have helped and will continue to help.

I hope documenting this will be useful to those in the future who fear the wrench, like me.


Thank you ADV'ers!